(i) Field of the Invention
The present invention relates to a therapeutic composition comprising at least one antigen, in particular an antigen of viral, bacterial or parasitic origin, or at least one in vivo generator of a compound comprising an amino acid sequence, and at least one adjuvant.
(ii) Description of Related Art
The use of adjuvants in therapeutic compositions of the vaccine type has been known for a long time. The main objective of these adjuvants is to allow an increase in the immune response. These adjuvants are diverse in nature. They may, for example, consist of liposomes, oily phases, for example the Freund type of adjuvants, generally used in the form of an emulsion with an aqueous phase, or, more commonly, may consist of water-insoluble inorganic salts. These inorganic salts may consist, for example, of aluminum hydroxide, zinc sulfate, colloidal iron hydroxide, calcium phosphate or calcium chloride. Aluminum hydroxide (Al(OH)3) is the most commonly used adjuvant. These adjuvants are described in particular in the article by Rajesh K. Gupta et al xe2x80x9cAdjuvants, balance between toxicity and adjuvanticityxe2x80x9d, Vaccine, Vol. 11, issue 3, 1993, pages 993-306.
The adjuvants mentioned above have the drawback of limited efficiency. Moreover, they may induce a certain toxicity with regard to individuals treated. More particularly, when these therapeutic compositions are injected, the formation of lesions and other local reactions such as granulomae is observed at the point of injection. These drawbacks are less pronounced when the adjuvant in aluminum hydroxide. Accordingly, the latter compound is one of the most commonly used adjuvants. Recently, however, aluminum hydroxide, like all aluminum-based compounds, has come to be suspected of being a factor promoting the appearance of certain diseases, such as renal dysfunctions or Alzheimer""s disease. In addition, it is known that aluminum hydroxide efficiently induces only humoral immunity and not cell immunity.
A first object of the invention is to provide therapeutic compositions comprising an adjuvant which allows an increase in the immune response which is at least equal to that imparted by aluminum hydroxide, without causing lesions or local reactions of the granuloma type and which is not liable to promote the appearance of diseases in the individual treated.
Another object of the invention is to provide a therapeutic composition comprising an adjuvant which efficiently induces both cell immunity and humoral immunity.
Yet another object of the invention is to provide a method for making a therapeutic composition using the adjuvant of the invention.
In a first aspect, the present invention relates to a therapeutic composition comprising (i) at least one antigen or at least one in vivo generator of a compound comprising an amino acid sequence and (ii) at least one adjuvant comprising at least one pharmaceutically acceptable and water-soluble salt of an organic anion and a metal cation.
In a second aspect, the present invention relates to a method of making a composition intended for the prevention or treatment of infectious diseases comprising combining (a) at least one adjuvant comprising at least one pharmaceutically acceptable and water-soluble salt of an organic anion and a metal cation and (b) at least one antigen or at least one in vivo generator of a compound comprising an amino acid sequence.
In a third aspect, the present invention relates to a method for treating a functional disease comprising administering to a patient the therapeutic composition as described above.
In another aspect, the invention relates to an adjuvant composition comprising a pharmaceutically acceptable and water-soluble salt and (a) an oily adjuvant, (b) a surfactant and/or (c) an oily adjuvant combined with a surfactant.
With the foregoing as well as other objects advantages and features of the invention that will become hereinafter apparent, the nature of the invention may be better understood by reference to the following detailed description of the preferred embodiments and to the appended claims.
In the sense of the present invention, a water-soluble salt may be such that its solubility in water is greater than or equal to 10 g/l, preferably between 10 and 2000 g/l.
The metal cation constituting said pharmaceutically acceptable salt is preferably a divalent cation. This cation is advantageously a cation of a metal chosen from the group consisting of manganese, calcium and zinc. Manganese is a very particularly preferred metal within the context of the present invention. The reason for this is that it has been observed that pharmaceutically acceptable and water-soluble salts according to the invention comprising an Mn2+ cation allow the induction of a particularly large immune response, while at the same time being low in toxicity.
The organic anion constituting said pharmaceutically acceptable salt is advantageously an anion of a compound comprising at least one oxygenated functional group, preferably a phosphoric group xe2x80x94PO4H2, or a carboxylic group xe2x80x94COOH.
Glycerophosphoric acid is a preferred anion containing a phosphoric group.
The preferred anions comprising at least one carboxylic group are derived from compounds chosen from:
acid saccharides, preferably acid saccharides having from 5 to 7 carbon atoms, more preferably those having 6 or 7 carbon atoms,
mono- or polycarboxylic acids,
amino acids.
The preferred mono- or polycarboxylic acids are fumaric acid and the compounds of the formula (I): 
Preferred compounds of formula (I) are acetic acid, lactic acid, tartaric acid, malic acid, citric acid and pyruvic acid.
In the sense of the present invention, an acid saccharide is of a saccharide comprising at least one carboxylic function, a saccharide being a glucide consisting of reducing sugars. These acid saccharides are advantageously aldose derivatives obtained by oxidation of the primary alcohol function or of the aldehyde function into a carboxylic function. Such compounds may most particularly include of gluconic acid, glucuronic acid, fructoheptonic acid, gluconoheptonic acid and glucoheptonic acid. When the organic anion is derived from an amino acid, this amino acid may be an xcex1-amino acid such as glutamic acid, methionine and, most particularly, aspartic acid.
A pharmaceutically acceptable, water-soluble salt according to the invention may comprise a polyvalent cation, especially a divalent cation, combined with an organic anion or with several organic anions of different nature. Thus, by way of example, a divalent cation such as the calcium cation may be combined with an anion derived from gluconoheptonic acid and an anion derived from gluconic acid.
A water-soluble adjuvant most particularly preferred within the context of the present invention consists of manganese gluconate.
A therapeutic composition according to the present invention may comprise between 0.01 and 1000 mg/ml, preferably between 0.1 and 150 mg/ml, of an adjuvant as defined above.
A therapeutic composition according to the invention may be prepared by simple mixing of an aqueous suspension containing the antigen or said in vivo generator with an aqueous solution of the salt defined above.
Besides the adjuvant comprising a pharmaceutically acceptable and water-soluble salt as defined above, the therapeutic composition according to the invention may also comprise an oily adjuvant. In such a case, the therapeutic composition according to the invention is advantageously in the form of an emulsion combining at least one aqueous phase and at least one oily phase.
This emulsion may be of the water-in-oil (W/O) type or, preferably, of the oil-in-water (O/V), water-in-oil-in-water (W/O/W) or microemulsion type. Such an emulsion may be prepared according to the standard methods for the preparation of an emulsion, in particular according to the processes described in patent applications EP-A-489,181 and EP-A-481,982. Thus, the oil constituting the oily phase may be emulsified, with stirring, with the aqueous phase including an aqueous solution or suspension containing the antigen.
An emulsion according to the invention may contain, by weight, from 0.5% to 99.5% of oily phase per 99.5% to 0.5% of aqueous phase, preferably from 5% to 95% of oily phase per 95 to 5% of aqueous phase and, more preferably, from 25 to 27% of oily phase per 75 to 25% of aqueous phase. The emulsion must be stable preferably for at least 12 months when it is stored at 4xc2x0 C.
The oily adjuvant may be a mineral oil, a non-mineral oil or a mixture of a mineral oil and a non-mineral oil. Said mineral oils may be natural or synthetic. Said non-mineral oils may be of plant, animal or synthetic origin. The non-mineral oils are advantageously metabolizable. All these oils are devoid of toxic effects with regard to the host organism into which the composition of the invention is administered. They are preferably liquid at the storage temperature (about +4xc2x0 C.) or at least make it possible to give emulsions which are liquid at this temperature. An advantageous mineral oil according to the invention may include an oil comprising a linear carbon chain having a number of carbon atoms preferably greater than 16, and free of aromatic compounds. Such oils may, for example, be those marketed under the name xe2x80x9cMARCOL 52xe2x80x9d (produced by Esso France) or xe2x80x9cDRAKEOL 6VRxe2x80x9d (produced by Penreco USA).
Examples of synthetic non-mineral oils which may be mentioned are polyisobutenes, polyisopropenes, esters of alcohols and fatty acids, such as, for example, ethyl oleate and isopropyl myristate, mono-, di- or triglycerides, propylene glycol esters, partial glycerides such as corn oil glycerides, for instance those marketed by the company SEPPIC under the name LANOL (trademark), maisin and oleyl oleate. Among the plant oils which may be mentioned are unsaturated oils rich in oleic acid which are biodegradable, for example groundnut oil, olive oil, sesame oil, soya oil or wheatgerm oil.
The animal oils may include in particular squalene, squalane or spermaceti oil.
Moreover, when it is in the form of an emulsion as defined above, the therapeutic composition according to the invention may also advantageously contain one or more surface-active agents. The latter agent has a lipophilic or hydrophilic nature characterized by an HLB (hydrophilic-lipophilic balance) value between 1 and 19.
Such a surfactant may include:
an alkylpolyglycoside or a mixture of alkyl-polyglycosides of formula Ra-(O)-Zn where Ra represents a linear or branched saturated aliphatic radical comprising from 4 to 24 carbon atoms, preferably from 8 to 22 carbon atoms, Z is a sugar residue, preferably glucose, and n is between 1 and 5, preferably between 1.1 and 2,
saponins,
lecithins,
polyoxyethylated alkanols such an those marketed under the name BRIJ by the company ICI,
polymers comprising polyoxyethylene and polyoxypropylene blocks, such as those marketed under the name PLURONIC by the company BASF.
Particularly preferred surfactants are polyethylene glycol esters obtained by condensation of a fatty acid, in particular a fatty acid which is liquid at 20xc2x0 C., with a polyethylene glycol of molecular weight between 80 and 2000; such a surfactant is marketed by the company SEPPIC under the tradename SIMULSOL 2599.
Another surface-active agent preferred within the context of the present invention is an ester obtained by condensation of a fatty acid, advantageously a fatty acid which is liquid at 20xc2x0 C., with a sugar, sorbitol, glycerol or a polyglycerol, preferably a polyglycerol comprising from 2 to 5 glycerol units. Said sugar may be glucose, sucrose or, preferably, mannitol. By way of particularly preferred mannitol ester, there may be mentioned mannitol oleates obtained by dehydration of the polyhydroxylated carbon chain of mannitol which undergoes 1-4 or 2-6 cyclization.
Derivatives of these sugar esters, of polyethylene glycol, of sorbitol, of glycerol or of polyglycerol may also be used. These derivatives have a hydrophilicity which is modified in particular by grafting hydrophilic functions such as alcohol, polyol, ethylene oxide, propylene oxide, carboxylic acid, amine or amide. Such derivatives may, for example, include polyoxyethylated fatty esters of sorbitan, such as the TWEENs (conf. International Cosmetic Ingredient Dictionary, 5th ed. 1993).
Another preferred type of surfactant is ethoxylated plant oils such as, for example, ethoxylated castor oil, this oil being optionally hydrogenated.
A surface-active agent according to the invention is preferably pharmaceutically acceptable for an injectable use; it must in particular be free of heavy metals and have very low acid numbers or peroxide numbers. It is also desirable for it to satisfy the harmlessness test standards such as, for example, those described by S. S. Berlin, Annals of Allergy, 1962, 20, 473 or the tests of abnormal toxicity described in the European Pharmacopoeia. The surface-active agent is preferably combined with the oily adjuvant before formation of the emulsion.
The concentration of surface-active agent in the therapeutic composition may be between 0.01 and 500 mg/ml, preferably between 0.1 and 200 mg/mi.
Oils associated with a surface-active agent (mannitol ester) which are most particularly suitable within the context of the present invention are those marketed by the company SEPPIC under the tradename xe2x80x9cMONTANIDExe2x80x9d. The nature of these oils, the type of emulsion which can be obtained with them and the properties (viscosity and conductivity) of these emulsions are featured in Table 1 below:
The oily adjuvant may also include a self-emulsifiable oil, that is to say an oily preparation capable of forming a stable emulsion with an aqueous phase, with virtually no energy input, for example by dispersion in the aqueous phase by slow mechanical stirring. In this respect, self-emulsifiable oils such as those known in the European Pharmacopoeia under the names Labrafil and Simulsol may be mentioned. These oils are polyglycolyzed glycerides.
Preferred self-emulsifiable oils are those described in French patent application No. 9500497 filed on Jan. 18, 1995, in the name of Applicant, entitled xe2x80x9cUtilisation of d""esters d""acides gras xc3xa9thoxylxc3xa9s comme composants auto- xc3xa9mulsionnables notamment utiles pour la prxc3xa9paration de compositions phytosanitaires ou de mxc3xa9dicaments xc3xa1 usage vxc3xa9txc3xa9rinarie ou humainxe2x80x9d [Use of exthoxylated fatty acid esters as self-emulsifiable components which are particularly useful for the preparation of plant-protection compositions or medicinal products for human or veterinary use]. These oils include ethoxylated fatty acid esters corresponding to one of the following formulae. 
in which:
R1 R3, R5, R6, R8 and R10 represent a saturated or unsaturated, linear or branched hydrocarbon chain having from 5 to 30 carbon atoms;
R2, R4, R7, and R9 represent a saturated or unsaturated, linear or branched hydrocarbon chain having from 1 to 5 carbon atoms;
the total number of ethylene oxide molecules represented in the abovementioned formulae II, III and IV by k, 1+m and n+p+q, respectively, being an integer such that the HLB value of said compounds is between about 4 and about 10, preferably between about 5 and about 9.
R1 is preferably chosen from palmitic, stearic, ricinoleic, oleic, linoleic and linolenic acid residues, R2 represents a methyl radical and k is an integer between 1 and 5, preferably equal to 2, and moreover the preferred ethoxylated fatty acid esters of formula III are those in which:
(i)xe2x80x94R6, R8 and R10 represent hydrocarbon chains having from 16 to 22 carbon atoms, corresponding in particular to the fatty chains of rapeseed oil, of corn oil, of soya oil, of groundnut oil and of apricot kernel oil,
xe2x80x94R7 and R9 represent a methylene group. CH2;
xe2x80x94n, p and q represent integers such that their sum is between 3 and 30, and preferably equal to 20; or
(ii)xe2x80x94R6, R8 and R10 represent hydrocarbon chains corresponding to the fatty chains of castor oil;
xe2x80x94R7 and R9 represent a methylene radical, CH2;
xe2x80x94n, p and q represent integers such that their sum is between 5 and 7.
The concentration of self-emulsifiable oil in the therapeutic composition according to the invention may be approximately between 5 and 700 g/l, preferably approximately between 10 and 500 g/l.
Besides the oily phase and the aqueous phase, the composition according to the invention may contain a conventional immunostimulatory agent such as Avridine(copyright), i.e. N,N-dioctadecyl-Nxe2x80x2, Nxe2x80x2-bis(2-hydroxyethyl)propanediamine, MDP (muramyl dipeptide) derivatives, especially threonyl-MDP, mycolic acid derivatives or Lipid A derivatives.
The therapeutic composition according to the invention may also comprise one or more surface-active agents, in the absence of any oily adjuvant.
The therapeutic composition is then in the form of a micellar solution. This may be prepared by simple mixing of the surface-active agent with a dispersion in water of the antigen or of the in vivo antigen generator.
The surface-active agent may be chosen from the surface-active agents described above, in combination with an oily adjuvant.
Said micellar solution may contain from 0.5 to 500 mg/ml, preferably from 1 to 250 mg/I, of surface-active agent.
A therapeutic composition according to the present invention may comprise an antigen such as a virus, a microorganism, more particularly a bacterium or parasite, or a compound comprising a peptide chain. Such a compound may include a protein or a glycoprotein, especially a protein or glycoprotein obtained from a microorganism, a synthetic peptide or a protein or a peptide obtained by genetic engineering. Said virus and microorganism may be totally inactivated or live and attenuated. By way of virus which may constitute an antigen according to the present invention, there may be mentioned the rabies virus, Aujeszky viruses, influenza viruses, the virus of foot-and-mouth disease or HIV viruses. By way of microorganism of bacterial type which may constitute an antigen according to the present invention, there may be mentioned E. coli and those of the genera Pasteurella, Furonculosis, Vibriosis, Staphylococcus and Streptococcus. By way of parasite, there may be mentioned those of the genera Trypanosoma, Plasmodium and Leishmania.
A therapeutic composition according to the invention comprises an antigen concentration which depends upon the nature of this antigen and on the nature of the individual treated. It is, however, particularly noteworthy that an adjuvant according to the invention, which may or may not be combined with an oily adjuvant and/or a surface-active agent as are defined above, makes it possible to decrease in an appreciable manner the usual dose of antigen required. The appropriate antigen concentration may be determined conventionally by those skilled in the art. This dose is generally of the order of 0.1 xcexcg/ml to 1 xcexc/ml, more generally between 1 xcexcg/ml and 100 mg/l.
A therapeutic composition according to the invention may also comprise an in vivo generator of a compound comprising an amino acid sequence, that is to say a biological compound capable of expressing such a compound in the host organism into which said in vivo generator has been introduced. The compound comprising the amino acid sequence may be a protein, a peptide or a glycoprotein.
These in vivo generators are generally obtained by genetic engineering processes.
More particularly, they may comprise living microorganisms, generally a virus, acting as a recombinant vector, into which is inserted a nucleotide sequence, in particular an exogenous gene. Those compounds are known as such and are used in particular as recombinant sub-unit vaccines.
In this regard, reference may be made to the article by M. Eloit et al., Journal of virology (1990) 71, 2925-2431, to International Application WO-A-91.00107 or to International Application WO-A-94/16681.
The microorganism constituting a recombinant sub-unit vaccine is advantageously a non-sheathed recombinant virus chosen, for example, from adenoviruses, the virus of the vaccine, canarypox virus, herpes viruses and baculoviruses. The exogenous gene inserted into the microorganism may, for example, be derived from an Aujeszky virus or HIV.
The in vivo generators according to the invention may also comprise a recombinant plasmid comprising an exogenous nucleotide sequence capable of expressing in a host organism a compound comprising an amino acid sequence. Such recombinant plasmids and their mode of administration into a host organism were described in 1990 by Lin et al., circulation 82:2217,2221; Cox et al., J. of Virol., Sept. 1993, 67, 9, 5664-5667 and in International Application WO/FR 95/00345 dated Mar. 21, 1995, in the name of the Applicant, entitled xe2x80x9cUne composition comprenant un plasmide recombinant et ses utilisations comme vaccin et medicamentxe2x80x9d [A composition comprising a recombinant plasmid and uses thereof as vaccine and medicinal product].
Depending on the nature of the nucleotide sequence comprised within the in vivo generator, the compound comprising the amino acid sequence which is expressed within the host organism may:
(i) be an antigen, and permit triggering of an immune reaction,
(ii) have a curative action with respect to a disease, essentially a functional disease, which has been triggered in the host organism. In this case, the in vivo generator allows a therapeutic treatment of the host, of the gene therapy type.
By way of example, such a curative action may comprise the in vivo cytokine generator, such as the interteukins, in particular interfeukin 2. The latter permit triggering or reinforcement of an immune reaction aimed at the selective removal of cancer cells.
The concentration of said in vivo generator in the therapeutic composition according to the invention depends, here also, in particular on the nature of said generator and on the host into which it is administered. This concentration may readily be determined by those skilled in the art, on the basis of routine experiment.
As a guide, it may, however, be pointed out that when the in vivo generator a recombinant microorganism, its concentration in the therapeutic composition according to the invention may be between 102 and 1015 microorganisms/ml, preferably between 105 and 1012 microorganisms/ml.
When the in vivo generator is a recombinant plasmid, its concentration in the therapeutic composition according to the invention may be between 0.01 and 100 g/l.
A therapeutic composition according to the invention may be used as a preventive or curative medicinal product. Depending on the nature of the antigen or of the in vivo generator, a therapeutic composition according to the invention may be administered to fish, to crustaceans such as shrimps, to poultry, in particular geese, turkeys, pigeons and chickens, to canines such as dogs, to felines such as cats, to pigs, primates, cattle, sheep and horses. The therapeutic composition according to the invention comprising a pharmaceutically acceptable water-soluble salt as defined above may also be administered to man. The therapeutic composition may be administered in a conventional manner, in particular by subcutaneous, intramuscular or intraperitoneal injection or via the oral or mucosal route.
Another aspect of the invention is use of an adjuvant comprising a pharmaceutically acceptable water-soluble salt as defined above for the preparation of a vaccine intended for the prevention or treatment of an infectious disease, in particular an infectious disease generated by a virus or a microorganism such as those mentioned above.
Another aspect of the invention is the use of a pharmaceutically acceptable water-soluble salt for the preparation of a therapeutic composition intended to treat a functional disease, such as cancer or mucoviscidosis.
In one other of these uses, said pharmaceutically acceptable salt may be combined with at least one of: an oily adjuvant, a surface-active agent and one oily adjuvant which is itself combined with a surface-active agent; these oily adjuvants and surfactants being as defined above.
Adjuvant compositions comprising said pharmaceutically acceptable salt and the oily adjuvant and/or the surfactants mentioned above constitute yet another aspect of the invention. Where appropriate, these adjuvant compositions comprise at least one aqueous phase.
In the latter case, the adjuvant compositions according to the invention, comprising at least one oily phase and, where appropriate, a surfactant, may be in the form of an emulsion. This emulsion may be of the W/O, O/W, W/O/W or microemulsion type.
These emulsions may comprise, by weight, from 0.5% to 99.5% of oily phase per 99.5% to 0.5% of aqueous phase, preferably from 5 to 95% of oily phase per 95 to 5% of aqueous phase and, more preferably, from 25 to 75% of oily phase per 75 to 25% of aqueous phase.
Where appropriate, they may comprise from 0.01 to 500 mg/ml, preferably from 0.1 to 200 mg/ml, of at least one surfactant.
When the adjuvant composition according to the invention comprises, besides the pharmaceutically acceptable salt and an aqueous phase, only one or more surfactants, it is then in the form of a micellar solution. The surfactant content of this micellar solution may be between 0.01 and 900 mg/ml, preferably between 1 and 250 mg/ml.
An adjuvant composition according to the invention usually comprises from 0.02 to 3000 mg/ml, preferably 0.1 to 1000 mg/ml and more preferably from 0.1 to 150 mg/ml, of a pharmaceutically acceptable salt according to the invention.
These compositions are useful for preparing the therapeutic compositions according to the invention.
The latter compositions may then be prepared by simple mixing of the adjuvant composition with a composition comprising an antigen or an in vivo generator of a compound comprising an amino acid sequence.